So I took note that the Panel Rooms will again be at the Fairmont for 2015.
I was wondering why they got switched from the Marriott this year and 2014. I can't speak for all attendees but at least for me the Fairmont is just so far off from the main convention center that I really couldn't squeeze room in to go to a panel last year. When in the Marriott it was much easier to just stroll into a random panel to waste some time in between other events/panels without making it a 10-15 min walk back and forth to the convention center. And it just seems like having everything localized in the convention center makes sense.
The Fairmont is more spacious, allowing for bigger panels and more organized lines. Less confusing snaked lines. Plus more people can see the all-time favorites about magikarp and cthulu and stuff